Valve-gear for locomotives.



PATENTED JUNE 27, 1905.

H. LENTZ.

VALVE GEAR FOB. LOCOMOTIVES.

APPLICATION FILED APR.13,1905.

2 SHBETS-SHEET 1.

5 O 9 1 7 2 E N U J D E T N E T A P H. LENTZ.

VALVE GEAR FOR LOCOMOTIVES.

APPLICATION FILED APR. 13, 1905.

2 SHEETS-SHEET 2.

NITED STATES Patented June 27, 1905.

PATENT OFFICE.

VALVE-GEAR FOR LOCOMOTIVES.

SPECIFICATION forming part of Letters Patent No. 793,596, dated June 27, 1905.

Application filed April 13, 1905. Serial No. 255,422.

To a w/wm it may concern:

Be it known that I, I-iUeo LENTZ, a subject of the German Emperor, residing at Berlin, in the Kingdom of Prussia,German Empire, have invented new and useful Improvements in Valve-Gears for Locomotives, of which the following is a specification.

IVith a view to more economical working hot high-pressure steam has of late been employed for driving locomotives. This has rendered necessary the construction of a more practical form of valve-gear, as slide-valves prove in practice to be but little adapted for distributing hot steam in comparison with puppet or lift valves.

My invention relates to a locomotive valvegear having a valve-rod working in a straight line, the valves being lifted by means of projections or lifting surfaces and rollers in wellknown manner.

Valve-gears in which valves are actuated by a lifting-rod moving in a straight line are generally known, but not of such construction as to be adapted for locomotives. Projecting valve-spindles and exposed valve-actuating parts are altogether unpracticable in locomotive working. The entire valve-gear must be inclosed dust-tight. This condition is fulfilled according to my invention not by the employment of a separate casing simply set over the parts, but by means of a valve-casing of peculiar construction which obviates the necessity for valve-spindle packings on the outside and at the same time renders the entire gear dust-tight. The setting and removal of such gear would, however, involve considerable expenditure of time and labor if each valve had to be accommodated separately. For this reason I employ for the whole of the valves of a cylinder one common valve-casing in which the lifter-rod which actuates all the valves reciprocates. In assembling the parts or removing the same it is merely necessary to bolt down or unscrew the valve-box cover. For this purpose the valve-casing presents four cross passages or bores running from a common longitudinal axis. The lifter-rod works in a common longitudinal bore, the valves themselves being guided by the four crossboresI In this manner the entire construction of the valve-gear is rendered exceedingly simple.

The invention therefore consists of a valvegear for locomotives the valves of which are actuated by a lifter-rod working in a straight line, said valves being located with the rod in a common casing having four cross-bores extending from a single longitudinal axis. The lifterrod reciprocates in the central bore,

while the four valves work in the four crossbores, so that the entire mechanism is effectively protected from dust and from the influence of the weather.

In the accompanying drawings, Figure 1 shows a longitudinal section of a valve-gear and below it the valve-box with a portion of the cylinder on which it is cast. Fig. 2 is a side elevation of the val ve-gear, the valve-box and a portion of the cylinder being also shown. Fig. 3 is an end elevation of the valve-gear. Fig. 4: shows a hot-steam locomotive provided with the new valve-gear.

Similar letters refer to similar parts throughout all the four views.

a is the valve-casing, 5 the longitudinal bore therein, and c o c 0 the cross-bores. In the bore 6 is located the rod f, provided with projection or lifting surfaces. This rod is reciprocated in well-known manner, whereby its lifting-surfaces pass below the rollers 1 WW 9"" and raise or let fall the valves 9 g g g secured to the frames 7c k 70 The bores c c 0 c are closed above by plugs d d (Z d" and below by the bushes 71c" 91 i for the valvestems h h 71, h. The longitudinal bore 1) is closed in front by the rod f and at the other end by a plug a. After loosening the bolts of the cover and releasing the rod from its actuating mechanism the cover, with all the parts, including the valves 7 g g can be removed and examined. The individual parts can be readily renewed when necessary.

The valve-casing may in some cases be constructed in separate parts. In Fig. 2, for instance, it is shown in two parts, each of which contains the two valves for one end of the cylinder.

In spite of the valve-actuating mechanism i being perfectly inclosed in a common easing,

1 only the valves are located in the steam-chamher, all other parts being separate from the latter.

The form of construction shown, with the bushes for the valve-stems at the bottom of the casing, renders a special centering-fillet on the cover unnecessary when the flanges of the said bushes serve likewise as centeringcovers.

Owing to the four cross-bores having no open apertures outward, no actual packing is necessary for the valve-stems. The necessity for stufling-boxes, which cause unnecessary waste of power and interfere with proper operation through jamming and pressing, is thus avoided. Between the valve-stem bushes, moreover, equalization of pressure can take place and the water condensed conducted ofii in common. Lubrication of the moving parts in the valve-casing is rendered very simple and safe.

Valve-gears for locomotives have also been designed in which in order to eflect good closure against dust and the influence of the weather the actual operating mechanism of the valves is located in the steam-chamber. My new method insures very considerably less clearance than usual with such. Furthermore, my invention greatly facilitates the change from slide-valve to lift-valve gear. For this purpose it is only necessary to replace the slide-valve cylinder by a lift-valve one with the new valve-casing and valves, so that the lifting-rod has then merely to be inserted instead of the slide-valve rod. The external link-motion, however, can remain unaltered, as shown in Fig. 4.

Having thus described my invention, whatl claim as new, and desire to secure by Letters Patent, is

Valve-gear'for locomotives, comprising a casing having a longitudinal bore and four cross-bores, four lift-valves working in the cross-bores, and a valve-lifting rod reciprocating in the longitudinal bore, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

HUGO LENTZ. Witnesses:

WOLDEMAR HAUrT, HENRY HASPER. 

